Field of the Invention
Provided are renewable modified fatty acids and modified natural oils derived from natural fatty acids and natural oils. These modified compounds may exhibit properties that differ from the natural starting material, e.g., solubility in various solvents, softening/liquid points, miscibility, flexibility, glass transition temperature, and/or solubilization potential.
The modified fatty acids and modified natural oils can be incorporated into a wide variety of compositions. Such compositions include, but are not limited to personal care (e.g., hair care, sun care, skin care, oral care), adhesives, coatings, paints, electronics, Household, Industrial and Institutional (HI&I) compositions, inks, membranes, metal working fluids, oilfield chemicals, plastics and plasticizers, textiles, industrial products, biocides, pharmaceuticals/nutritionals, and agrochemical compositions.
Description of Related Art
Natural fatty acids, such as palmitate, stearate, oleate, linoleanate, and linoleate, and natural oils, such as soybean and linseed oils, are one of the most promising raw materials for the synthesis of renewable compounds, including polymers, plastics, and plasticizers. These natural materials are inexpensive, highly abundant, come from reliable and sustainable sources, and have high potential for modification. Natural oils are generally blends of different triglycerides, the esterification product of fatty acids and glycerol, and contain varying degrees of unsaturation (i.e., double bonds). Oils can be characterized by a hydroxyl value and the fatty acid compositions. Both natural fatty acids and natural oils must be chemically modified to make them sufficiently reactive to allow structural alterations and polymerizations to occur because the olefin functional groups are relatively unreactive. Unsaturated double bonds in this compounds have been converted to epoxide functional groups and succinic anhydride functional groups, allowing the addition of many hydroxyl containing species to be introduced into the natural oils. Examples of such epoxidized natural oils and the products derived from the epoxides are disclosed in U.S. Pat. Nos. 3,066,159; 5,973,082; and 7,691,914. 4,244,829; 4,886,893; 4,962,179; 5,232,968; 6,890,967; as well as E.P. patents 437,001; 981,321; 1,117,377; 1,338,630; 1,813,311; and G.B. patents 772,151 and 825,691. Each of these patents is incorporated in its entirety by reference. These fatty acids provide functionality in many different types of products, ranging from lubricating oils, printing inks, agricultural treatments, coatings, personal care compositions, emollients, detergents/soaps, and plasticizers.
Epoxidized and maleated natural oils are natural oils that have been chemically functionalized by the chemical addition of epoxide (oxirane) and succinic anhydride functional groups. Examples include epoxidized and maleated soybean oil and linseed oil, although, as will be discussed later, unsaturated natural oils lend themselves to these chemical functionalizations. Epoxidized soybean oil (ESO), which is environmentally friendly, renewable, and biodegradable, finds use as a plasticizer for polymer, for improving polymer mechanical strength, and in formulating inks, coatings, and lubricants. In addition, ESO and a related compound, maleated soybean, are both known to the personal care industry.
A discussion of epoxidized rapeseed oil modified by alcohols of varying chain lengths is provided in the article “Modification of rapeseed oil and its lubricating characteristics,” by Q. H. Li and D. H. Tao, published in J. Shanghai Jiaotong Univ., 43, 12, Dec.2009, p. 1953.
Other disclosures of related compounds include U.S. Pat. Nos. 3,066,159; 6,057,375; and 7,691,914. Each of the U.S., E.P., and G.P. patents and the journal article cited above are hereby incorporated its entirety by reference.
Despite the renewability, biodegradability, sustainability, and beneficial functions provided by natural fatty acids, natural oils and their epoxidized/maleated counterparts, they exhibit properties that can limit their application. For example, both ESO and maleated soybean oil are insoluble and non-dispersible in water or alcohols. As a result, these fatty acids and oils may tend to exude or phase-separate from formulated compositions. This feature makes their formulation more difficult, often requiring additional ingredients to facilitate solutions, emulsions, or dispersions. Natural and epoxidized/maleated natural oils may not impart the desired property needed in end-uses, such as solubilization capability, glass transition, flexibility, shine, and/or plasticization. Consequently, the performance (including, but not limited to stability, resistance to phase separation, absorption, clean-up, solubility potential, staining potential, lubrication, film formation, uniformity of spreading, comedogenic tendency, ease of removal), and aesthetic qualities (such as skin-feel, greasiness, shiny appearance) may be less than desired. Finally, although such fatty acids and oils are an important renewable material, they are not always the formulator's first choice, and, in fact, often are not considered at all.
Accordingly, there is a need for materials that are renewable, natural, and biodegradable having different and controllable chemical, physical, and/or mechanical properties such that the limitations found in natural and epoxidized/maleated natural oils are minimized or eliminated.